This invention relates generally to window and other building portal protection and, more specifically, to methods and apparatus for protecting windows and other building portals against wind, airborne moving objects, and other conditions likely to cause damage to the portal structure or, upon entry, to an interior of the building.
A variety of structures for shutters, for houses, apartments, motels, hotels and other commercial buildings are known in the building arts. Shutters may be, but are typically not installed for permanent or semi-permanent coverage over their associated portal. More typically, shutters are selectively movable and securable into open and shut modes using, for example, a hinge and latch mechanism.
Examples of known shutter types include rolling shutters, accordion shutters, removable and stowable panels, “Bahama” shutters, and “Colonial” shutters.
Rolling shutters, or roll shutters, include a plurality of parallel abutting slats, hinged to one another or attached at their respective ends to flexible support strips. A coiling mechanism selectively winds the slats into a bundle above the window, and unwinds them such that they collectively cover the window. Rolling shutters offer substantial protection but have shortcomings, such as blocking the view and the airflow through the portal when they are closed, that makes them undesirable for many applications.
Accordion shutters generally comprise an assembly of hinged, interlocking aluminum or steel blades that move horizontally between an upper and lower track. The blades are substantially abutting and parallel to one another when the assembly is extended across the window, and fold into a stack, accordion-style, when the assembly is moved to its open position. For larger areas there are two blade assemblies, that meet in the middle of the window portal when closed, and which moves toward the right and left, respectively, to assume an open position.
Removable and stowable panels are typically a low-cost, effective protection. Variations include plywood that is nailed or bolted to the building exterior, and corrugated metal covers that fit into tracks that are permanently installed above and beneath the windows. Although simple and relatively low cost, these typically require considerable manual effort to install and remove, and require substantial, accessible storage space.
“Bahama” and “Colonial” style shutters are respective styles of louvered shutter assemblies that are hinged to swing open and shut over a window or other portal. The Bahama style is a single panel shutter, the panel having a slightly larger area than that of its associated window. The top of the shutter is attached to a hinge mechanism having a pivot axis above the window opening. The shutter is supported in its open position by two removable struts, at an angle of approximately 45 degrees. The shutter is closed to serve as a window protection by removing the two rods, allowing the shutter to lie flat against the building and over the window. A sliding pin then locks it. The Colonial style is a two-panel shutter, each panel attached to a hinge extending vertically at either side of the window. The shutters are moved to their open position by swinging each outward until it lies flat against the building, one at each side of the window. The shutters are closed by folding each inward until each is flat over its half of the window. A latch holds the shutter panels in their closed position.
The outer frame of the Bahama shutters, and of each of the two halves of the Colonial shutter, is typically formed of four abutting members, screwed or welded together at the respective ends. U.S. Pat. No. 5,907,929, at FIGS. 2 and 6, depicts an example of a screwed-together abutting end.
The present inventors have identified that although the known types and examples of shutters may provide certain forms of protection for windows and portals, a need exists for reduced weight, increased strength, extended life, and ease of installation and operation.
For example, the screw connection of the rails of the Bahama shutters depicted by U.S. Pat. No. 5,907,929 may fail due to environmental conditions such as, for example, repeated wind-induced flexing of the shutter and its peripheral rails. Similarly, welded butt joints at the corners of the shutter frame have a probability of failing, due to repeated flexing of the joints or to defects in the original weld quality.